1. Field Of The Invention
The present invention relates to an improved lens system adapted for use in conditions of low or diffuse lighting, and, more specifically, it relates to such a system which has a capability of collecting and concentrating the available light.
2. Description Of The Prior Art
Various means have been known to assist individuals who are visually impaired. For example, millions of people employ corrective lenses in the form of contact lenses or eyeglasses in order to minimize or overcome a wide variety of problems.
It has been known to employ optical devices such as telescopes based on Galilean or Kepler optics.
With respect to people who are partially sighted the problem becomes more severe. It has been known to provide various forms of eyeglasses to provide some assistance to such individuals. It has also been known to provide single or multiple magnifying lenses in various sorts of holders to enlarge the image that the partially sighted would otherwise receive.
In spite of the foregoing prior art teachings, there is lacking any means for effectively assisting the partially sighted through a means which collects and concentrates the available light to thereby provide for improved vision under conditions of low or diffuse lighting.
U.S. Pat. No. 1,716,308 discloses a condenser lens system for a microscope wherein entry through the lens lateral surface is contemplated.
U.S. Pat. No. 3,368,078 discloses a relay lens which is employed to focus radiant energy on an aplanat having a hyperhemispherical surface and a hemispherical surface. Delivery of radiant energy to a sensor is contemplated.
U.S. Pat. No. 3,535,015 discloses a lens system usable in a microscope or telescope.
U.S. Pat. No. 3,592,525 discloses an ophthalmic surgery spectacle having large and small lenses and an interposed source of illumination.
There remains a substantial need for a lens system which efficiently collects and concentrates available light for uses, such as in a prosthesis.
There is also a need for improved lens systems adapted for improved low light performance in uses such as cameras and microsurgery.